JPH0148038B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a clothes dryer that detects the end of drying using a change in drum exhaust temperature.

BACKGROUND OF THE INVENTION In recent years, clothes dryers that use various methods to detect the end of drying have been invented, but among these, the most commonly used is one that uses changes in drum exhaust temperature to detect the end of drying. .

Problems to be Solved by the Invention However, in conventional clothes dryers, especially when the amount of clothes is small, as the drum rotates, the clothes are lifted upwards in the drum by a buttful provided in the drum and rolled. They fall into the lower part of the drum and have little chance of coming into contact with the hot air that flows through the center of the drum from the inlet to the outlet. Therefore, the proportion of air heated by the heater that is directly exhausted without contributing to drying the clothes increases, and the exhaust temperature of the drum rises rapidly compared to when drying clothes of the rated capacity. , its temperature also increases.
When the exhaust gas temperature reaches a predetermined temperature set for safety (hereinafter referred to as the predetermined temperature), the temperature is adjusted, and the exhaust temperature change curve is disturbed, making it impossible to properly detect the end of drying. It had some problems.

In view of the above problems, the present invention provides a clothes dryer that can appropriately detect the end of drying even when drying a small amount of clothes.

Means for Solving the Problems In order to achieve the above object, the clothes dryer of the present invention includes a drum for storing clothes, a heater and a fan for supplying hot air, a motor for driving the drum and the fan, and a drum for storing the clothes. A temperature detection section detects the exhaust temperature, and if the drum exhaust temperature detected by this temperature detection section exceeds a predetermined temperature during the preheating period, it is determined that there is a small amount of clothing, and the subsequent drying process is continued for a predetermined time. and a control section that causes delayed operation.

Effect With the above configuration, the control unit detects the drum exhaust temperature using the temperature detection unit, detects the time when the amount of temperature change over time falls below a certain value as the end of the preheating period, and detects the rated capacity. Drying operation is performed according to the drying process, and if the drum exhaust temperature reaches a predetermined temperature or higher before the end of the preheating period, it is determined that there is a small amount of clothing, and the subsequent drying process is delayed for a certain period of time. to move to.

Embodiment An embodiment of the present invention will be described with reference to FIG. 1st
In the figure, 1 is a drum for storing clothes, 2 is a heater for heating the air, 3 is a fan for blowing hot air obtained by the heater 2 into the drum 1, and 4 is for rotating the drum 1 and the fan 3. The motor 5 is installed in the exhaust path of the drum 1.
An exhaust temperature detection section 6 is a control section that receives the output of the exhaust temperature detection section 5 and controls the driving of the heater 2 and the motor 4.

When the clothes dryer having the above configuration is operated, the air heated by the heater 2 heats the clothes in the drum 1, thereby increasing the exhaust temperature of the drum 1. This situation is shown in FIG. Figure 2a shows the case when a quantity of clothes equal to the rated capacity, for example 2 kg, is dried, and Figure 2b shows the case when a small amount of clothes, for example 0.5 kg, is dried. In other words, when the amount of clothes is large, the drum exhaust temperature enters a preheating period where it increases as soon as drying begins, and after a certain period of time, the temperature becomes stable at a constant rate drying period, whereas when the amount of clothes is small In this case, the proportion of the air heated by the heater 2 contributing to drying is small, and the drum exhaust temperature rises rapidly, reaching a predetermined temperature during the preheating period before transitioning to the constant rate drying period. The temperature is controlled so that it does not rise above that temperature.

Next, the control of the drying process sequence performed by the control section 6 will be explained with reference to FIG.
In this example, the drum exhaust temperature changes over 6 minutes.
The time when the temperature is within 2deg is determined as the end of the preheating period,
The drum exhaust temperature is also detected once every 10 seconds.
When the temperature reaches a predetermined temperature, for example 65℃, turn on heater 2.
OFF control. If the amount of clothing is small, see Figure 2b.
As shown in FIG. 2, the exhaust temperature rises rapidly from the beginning of drying, and reaches a predetermined temperature without detecting the end of the preheating period, as shown in FIG. 2a. In this way, if the predetermined temperature is reached before the end of the preheating period is detected, the control unit 6 maintains the predetermined temperature and shifts the sequence to a fixed time delay operation. In this embodiment, the operation is performed with a delay of 30 minutes.

If the drum exhaust temperature does not reach the predetermined temperature before the end of the preheating period is detected (Figure 2 a), it is determined that there is not a small amount of clothing, and the normal sequence of detecting the end of drying based on the temperature change is executed. be done.

In this example, when the amount of clothing was less than 0.7 kg, it was determined that the amount of clothing was small, and the drying could be performed without any problem by delaying operation for 30 minutes. Note that the amount by which it is determined that there is a small amount of clothing is not limited to the amount described in this embodiment, as it goes without saying that there is a degree of freedom depending on the rated capacity and structure of the dryer.

Further, in this embodiment, the predetermined temperature at which the delayed operation is started is set for the safety of the equipment, but the same effect can be obtained even if the predetermined temperature is set to an appropriate temperature below this temperature.

Effects of the Invention As described above, the present invention determines that there is a small amount of clothing when the exhaust gas temperature reaches a predetermined temperature during the preheating period, so even if the amount of clothing is small, it is possible to dry the clothing without any problem. It is something that can be done.

[Brief explanation of drawings]

Figure 1 is a structural block diagram of a clothes dryer according to an embodiment of the present invention, Figure 2a is a characteristic diagram of the change in drum exhaust temperature at rated capacity load, and Figure 2b is a change in drum exhaust temperature at a small load. The characteristic diagram, FIG. 3, is a flowchart of the drying process sequence of this embodiment. 1...drum, 2...heater, 3...fan,
4...Motor, 5...Temperature detection section, 6...Control section.

Claims (1)

[Scope of Claims] 1. A drum for storing clothes, a heater and a fan for sending hot air to the drum, a motor for driving the drum and the fan, a temperature detecting section for detecting the temperature of the exhaust gas from the drum, and a temperature detecting section for detecting the exhaust temperature of the drum. The drive of the heater and the motor is controlled by using the output of the detection section as input, and if the detected exhaust temperature exceeds a predetermined temperature during the preheating period, it is determined that there is a small amount of clothing in the drum, and the following steps are performed. A clothes dryer equipped with a control section that shifts the drying process to delayed operation for a predetermined period of time. 2. The clothes dryer according to claim 1, wherein the control section shifts to delayed operation when the exhaust temperature of the drum reaches a predetermined temperature set for safety. 3. The clothes dryer according to claim 1, wherein the control section determines that the preheating period has ended when the amount of change over time in the drum exhaust temperature becomes equal to or less than a predetermined value.